Clinical Research Directory

LBBAP Versus ILR in Patients With New-Onset LBBB and Moderately Reduced LVEF After TAVI

Patients with new-onset complete LBBB (QRS \> 120 ms, persisting \> 24 h after TAVI) and moderately reduced LVEF (35-50%) will be screened in participating centers. Eligible patients will be centrally randomized 1:1 (stratified by center and atrial fibrillation (yes/no)) to either: * Experimental arm: Left bundle branch area pacing (LBB(AP)) with Biotronik pacemaker and dedicated conduction system pacing leads. * Control arm: Implantable loop recorder (ILR, Biotronik BIOMONITOR IV) for rhythm monitoring. The occurrence of the following events within 12 months of randomization will be evaluated: hospitalization for heart failure, syncope or hemodynamically significant dizziness, or high-grade atrioventricular conduction disturbance. The impact of LBB(AP) compared to ILR monitoring will be evaluated at 6, 12, 24, and 36 months regarding: incidence of atrial fibrillation; incidence of non-sustained ventricular tachycardia; evolution of left ventricular ejection fraction; quality of life; hospitalizations; mortality; medico-economic outcomes; qccurrence of high-grade AV conduction disorders beyond 12 months; omplications related to pacemaker or ILR implantation; unscheduled pacemaker implantation in the ILR group. Patients will be monitored following a regular schedule that includes clinical visits, transthoracic echocardiography , ECG, remote device monitoring, and EQ-5D at 6, 12, 24 and 36 months.

Clinical Efficacy and Safety of Left Bundle Branch Area Pacing Using Quantitative Guidance of Multimodal Data in the Treatment of Heart Failure

Heart failure is a common chronic cardiovascular disease that seriously impairs patients' quality of life and long-term prognosis. When heart failure is complicated by complete left bundle branch block, the electrical signals that regulate orderly heart contraction cannot be transmitted normally along the left conduction pathway, causing the left and right ventricles to contract out of sync. This will gradually weaken the heart's pumping capacity, leading to symptoms such as exertional shortness of breath, persistent fatigue and body edema, and significantly increasing the risk of repeated hospital admissions and premature death. Traditional biventricular pacing is the standard treatment recommended by international clinical guidelines for this condition. By implanting pacing leads in both ventricles to deliver synchronized electrical stimulation, it restores cardiac synchrony, improves cardiac function and reduces mortality in most eligible patients. However, the placement of left ventricular leads is entirely dependent on the anatomy of the coronary venous system. Due to wide individual differences in venous structure, many patients encounter intraoperative difficulties such as failed coronary sinus intubation, absence of suitable target veins, phrenic nerve stimulation, high pacing thresholds and postoperative lead displacement. More importantly, approximately 30% to 40% of patients still show no significant improvement in cardiac function or symptoms even after optimized device programming, a condition known as non-response to cardiac resynchronization therapy. Left bundle branch area pacing is an innovative physiological pacing technique originally developed in China. It advances a pacing lead through the ventricular septum to directly activate the heart's intrinsic conduction bundle, allowing electrical impulses to spread along the natural conduction pathway and restore ventricular synchrony. Previous single-center observational studies have shown that this technique features stable long-term pacing parameters, relatively low operative difficulty and a favorable safety profile, and can achieve satisfactory cardiac resynchronization effects. Nevertheless, there is still a lack of high-quality multicenter randomized controlled evidence to confirm its long-term clinical hard endpoint benefits. In addition, current implantation operations largely rely on the personal experience of operators, without a unified quantitative positioning standard. This multicenter prospective randomized controlled study is led by the Second Affiliated Hospital of Nanchang University, with three other tertiary general hospitals participating. A total of 100 eligible heart failure patients with left bundle branch block and left ventricular ejection fraction ≤ 40% will be enrolled. All participants have received at least 3 months of standardized guideline-directed anti-heart failure drug therapy before enrollment, and will be randomly assigned to two groups at a 1:1 ratio. One group will receive left bundle branch area pacing guided by multimodal quantitative data, and the other will receive traditional biventricular pacing. If the initially assigned pacing strategy cannot be successfully implemented during surgery, the patient will cross over to the alternative approach to ensure clinical safety and therapeutic effect. After the implantation procedure, all patients will receive regular follow-up every 3 months for at least 1 year. During follow-up, the research team will perform examinations including 12-lead electrocardiogram, echocardiogram, 6-minute walk test and pacemaker device interrogation, and systematically record clinical events such as all-cause death, heart failure rehospitalization, malignant arrhythmia and procedure-related complications. The core goal of this study is to compare the incidence of the composite endpoint of all-cause death and heart failure rehospitalization between the two groups, and verify whether multimodal quantitative-guided left bundle branch area pacing can bring superior long-term clinical benefits to heart failure patients. The findings are expected to provide reliable evidence for the clinical application of this technique, help establish standardized quantitative implantation standards, and offer a more optimized treatment option for more heart failure patients.

REstoration of SYNChronous Cardiac Function Due to Physiologic cArdiac Pacing Modalities With Clinical Endpoints

The goal of this observational study is to evaluate the long-term clinical outcomes of physiologic cardiac resynchronization therapy (CRT) using conduction system pacing strategies compared with conventional biventricular CRT in patients with heart failure with reduced ejection fraction (HFrEF) and electrical dyssynchrony. The main questions it aims to answer are: * Does physiologic CRT (including left bundle branch area pacing \[LBBAP\] and LBBAP-optimized CRT) reduce the combined risk of all-cause mortality and heart failure hospitalization compared with conventional biventricular CRT? * Does physiologic CRT improve cardiac function and reverse ventricular remodeling more effectively than conventional CRT? Participants receiving physiologic CRT as part of routine clinical care will undergo standard follow-up evaluations, including electrocardiography, echocardiography, laboratory testing, and device interrogation. Clinical outcomes will be collected prospectively for 24 months and compared with a historical cohort of patients treated with conventional biventricular CRT. The study will assess clinical outcomes, echocardiographic response, electrical resynchronization parameters, and device-related safety in a real-world heart failure population.

Machine Learning for Diagnosis of Occlusive MI in LBBB Patients

This study investigates a new way to diagnose severe heart attacks in patients who have a specific electrical heart pattern called a Left Bundle Branch Block (LBBB). When patients present to the emergency department with chest pain, doctors routinely perform an electrocardiogram (ECG) to check for a heart attack. However, the presence of an LBBB can alter the heart's electrical signals on the ECG, effectively masking or hiding the typical signs of an ongoing acute coronary occlusion (a completely blocked artery). This making it highly challenging for emergency physicians to make an accurate and rapid diagnosis. The primary purpose of this prospective and observational research is to develop and evaluate an artificial intelligence/machine learning (ML) model that can analyze digital 12-lead ECG signals to accurately predict a true blocked coronary artery in patients with LBBB. The machine learning model will analyze raw digital ECG waveforms to detect subtle, microscopic patterns that might be missed by the human eye. To confirm the accuracy of the model, its predictions will be compared directly with invasive coronary angiography results, which is the gold standard reference method used to visualize blocked vessels. Additionally, the study aims to evaluate if the model can differentiate between a true heart attack caused by a blocked artery (Type 1 MI) and other non-occlusive conditions that cause elevated heart enzymes (Type 2 MI). Ultimately, the investigators intend to determine whether integrating this machine learning tool into emergency care can safely reduce the rate of unnecessary emergency invasive procedures for patients who do not have a true coronary blockage.

UHF ECG in LBBB and Response to CRT Prediction

The main objective of the project is to demonstrate that in patients with heart failure and QRS complex of nonRBBB morphology lasting over 130 ms, UHF-ECG can differentiate patients with trueLBBB from IVCD better than existing approaches based on the assessment of QRS complex morphology and duration from 12-lead ECG. Another goal of the proposed study is to demonstrate that trueLBBB patients will benefit more from CRT using left bundle branch pacing than from CRT using biventricular pacing. The final aim of the project is to demonstrate that the echocardiographic and clinical response in patients with intraventricular conduction disturbance will be dependent on the degree of reduction in ventricular dyssynchrony after CRT.

EArly Effect of Glucocorticoid on Incidence of Persistent Left BundlE Branch Block (LBBB) Post-TAVR (EAGLE-TAVR Trial)

Transcatheter aortic valve replacement (TAVR) has become an established alternative for the treatment of severe symptomatic aortic stenosis irrespective of surgical risk. The development of new-onset left bundle branch block (LBBB) is the most common complication, which impairs outcomes after TAVR. Glucocorticoid has been proven safe and effective in arrythmia after cardiac surgery. The anti-inflammatory effect of glucocorticoid may alleviate the occurrence of LBBB and thus the prognosis. EAGLE-TAVR is a multi-center, randomized, double blind, placebo-controlled trial. A total of 200 patients selected to undergo TAVR will be randomized in a 1:1 ratio to the treatment with intravenous Methylprednisolone 1mg/kg/day or placebo for 3 days started from the day of the procedure. According to the definition of the Valve Academic Research Consortium 3, persistent LBBB is defined as present LBBB at discharge or \>7 days post-TAVR. The primary endpoint is the occurrence of new-onset LBBB at 30 days post TAVR.